Casting components made from a tool steel

Abstract

A method of casting non-ferrous metals such as aluminum, magnesium, or zinc alloys uses casting components made from a tool steel comprising effective amounts of carbon, silicon, manganese, chromium, molybdenum, and vanadium, optional amounts of cobalt and increased level of molybdenum. Using the tool steel as a casting component, particularly as a mold, provides improvements in corrosion resistance, oxidation resistance, softening resistance, degradation resistance and deformation resistance. The tool steel casting component has a chromium oxide layer which is formed, in one mode, during the casting operation, to enhance the life and durability of the casting component and improve its casting performance.

What is claimed is:  
     
       1. A casting component having at least one surface for contacting molten non-ferrous and made of a steel composition comprising, in weight percent: 
       from about 0.05 to about 0.2% carbon;  
       from about 0.10 to about 1.5 silicon;  
       from about 0.1 to about 1.5% manganese;  
       up to 2.0% nickel;  
       from about 7.0 to about 15% chromium;  
       up to 2.0% copper;  
       up to 1.0% molybdenum;  
       up to 3% tungsten;  
       from about 0.05 to about 1.5% vanadium;  
       up to 0.5% niobium;  
       up to 0.1% aluminum;  
       up to 0.1% nitrogen;  
       up to 0.02% boron;  
       up to 0.05% titanium;  
       up to 0.015% sulfur;  
       essentially no cobalt;  
       with the balance being iron and inevitable impurities. 
     
     
       2. The casting component of  claim 1 , further comprising a chromium oxide layer adjacent a matrix formed of the steel composition of the casting component. 
     
     
       3. The casting component of  claim 2 , wherein the chromium oxide layer is positioned between the matrix and an outer iron oxide layer. 
     
     
       4. The casting component of  claim 1 , wherein the casting component is one of a mold, a core, a sleeve, an insert, a stalk; a plunger, a cylinder, a nozzle, a nozzle seat, a plunger tip, a ladle, a shot chamber, a tube, an ejection pin, a sprue spreader, and a ram. 
     
     
       5. The casting component of  claim 4 , wherein the casting component is a mold. 
     
     
       6. The casting component of  claim 5 , wherein the mold has at least a portion covered with a mold coating that is applied to the casting component prior to molten non-ferrous metal contact with the mold portion as part of a casting method. 
     
     
       7. The casting component of  claim 1 , wherein the casting component has at least a portion covered with a protective coating that is applied to the casting component prior to molten non-ferrous metal contact with the casting component. 
     
     
       8. The casting component of  claim 2 , wherein the chromium oxide layer has a thickness ranging between about 1 and 30 microns. 
     
     
       9. A casting component having at least one surface for contacting molten non-ferrous and made of a steel composition comprising, in weight percent: 
       from about 0.05 to about 0.4% carbon;  
       from about 0.10 to about 1.5 silicon;  
       from about 0.1 to about 1.5% manganese;  
       up to 2.0% nickel;  
       from about 7.0 to about 15% chromium;  
       up to 2.0% copper;  
       from 3.0 to 7.0% molybdenum;  
       up to 3% tungsten;  
       from about 0.05 to about 1.5% vanadium;  
       up to 0.5% niobium;  
       up to 0.1% aluminum;  
       up to 0.1% nitrogen;  
       up to 0.02% boron;  
       up to 0.05% titanium;  
       from 1 to 10% cobalt;  
       up to 0.015% sulfur;  
       with the balance being iron and inevitable impurities. 
     
     
       10. The casting component of  claim 9 , wherein the casting component is one of a mold, a core, a sleeve, an insert, a stalk; a plunger, a cylinder, a nozzle, a nozzle seat, a plunger tip, a ladle, a shot chamber, a tube, an ejection pin, a sprue spreader, and a ram. 
     
     
       11. The casting component of  claim 10 , wherein the casting component is a mold. 
     
     
       12. The casting component of  claim 11 , wherein the mold has at least a portion covered with a mold coating that is applied to the casting component prior to molten non-ferrous metal contact with the casting component as part of a casting method. 
     
     
       13. The casting component of  claim 9 , wherein the casting component has at least a portion covered with a protective coating that is applied to the casting component prior to molten non-ferrous metal contact with the casting component. 
     
     
       14. The casting component of  claim 9 , further comprising a chromium oxide layer adjacent a matrix formed of the steel composition of the casting component. 
     
     
       15. The casting component of  claim 14 , wherein the chromium oxide layer is positioned between the matrix and an outer iron oxide layer. 
     
     
       16. The casting component of  claim 14 , wherein the chromium oxide layer has a thickness ranging between about 1 and 30 microns.